What LLD problems are asked at Google?

Google commonly asks Low Level Design problems including: Design an Elevator System, Designing a Logging Framework, Designing a Task Management System, Design an ATM System, Designing a Tic Tac Toe Game. These problems test your object-oriented design skills, knowledge of design patterns, and ability to create scalable, maintainable systems.

How to prepare for Google LLD interview?

To prepare for Google LLD interviews: 1) Practice common problems like Design an Elevator System, Designing a Logging Framework, Designing a Task Management System. 2) Master design patterns (Factory, Strategy, Observer, Singleton). 3) Learn to create UML class diagrams. 4) Practice in your preferred language (Python, Java, C++). Use our interactive playground with step-by-step guidance and AI code review.

What programming languages should I know for Google LLD interview?

Google typically allows candidates to use their preferred language. Popular choices include Python, Java, C++, JavaScript/TypeScript, and C#. Our playground supports all these languages with syntax highlighting, code execution, and complete solution references.

How long are Google LLD interview rounds?

Google LLD/Machine Coding rounds typically last 45-60 minutes. You're expected to gather requirements, design classes and relationships, implement core functionality, and discuss trade-offs. Practice with our timed problems to build speed and confidence.

Google LLD Questions | LowLevelDesign

EasyFree

Design a File System - LLD Interview Problem. Master hierarchical structures & path resolution. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+4

15–30 min4 steps · 150 XP

EasyFree

Design an Elevator System - LLD Interview Problem. Master request dispatching & state management. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

15–30 min4 steps · 150 XP

BeginnerFree

Tutorial: Design a Parking Lot System - LLD Interview Problem. Master Singleton & Factory patterns. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

20–45 min4 steps · 100 XP

EasyPro

Design a Coffee Machine - LLD Interview Problem. Master state patterns & inventory management. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+6

15–30 min4 steps · 150 XP

EasyPro

Design a JSON Parser - LLD Interview Problem. Master recursive descent parsing & tokenization. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+6

15–30 min4 steps · 150 XP

EasyPro

Design a Movie Ticket Booking System - LLD Interview Problem. Master concurrent seat allocation & locking. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+6

15–30 min4 steps · 150 XP

EasyPro

Design a Trie (Prefix Tree) - LLD Interview Problem. Master prefix matching, autocomplete & DFS traversal. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+8

15–30 min4 steps · 150 XP

EasyPro

Design a Vending Machine - LLD Interview Problem. Master state machine & change calculation. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

15–30 min4 steps · 150 XP

EasyPro

Design an LRU Cache - LLD Interview Problem. Master HashMap + Doubly Linked List for O(1) operations. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+6

15–30 min4 steps · 150 XP

EasyPro

Design a Logging Framework - LLD Interview Problem. Master handler chains & formatting strategies. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

15–30 min4 steps · 150 XP

EasyPro

Design a Task Management System - LLD Interview Problem. Master state transitions & observer pattern. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

15–30 min4 steps · 150 XP

EasyPro

Design a Tic Tac Toe Game - LLD Interview Problem. Master grid logic & win detection. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

15–30 min4 steps · 150 XP

MediumPro

Design a Meeting Room Reservation System - LLD Interview Problem. Master conflict detection & recurring bookings. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

30–60 min4 steps · 200 XP

MediumPro

Design a Meeting Room Scheduler - List Bookings - LLD Interview Problem. Master filtering & pagination. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

30–60 min4 steps · 200 XP

MediumPro

Design a Rate Limiter - LLD Interview Problem. Master token bucket & sliding window algorithms. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

30–60 min4 steps · 200 XP

MediumPro

Design an Elevator System - Multiple Lifts - LLD Interview Problem. Master load balancing & request distribution. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

30–60 min4 steps · 250 XP

MediumPro

Design a Train Platform Management System - LLD Interview Problem. Master platform assignment & schedule management. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

30–60 min4 steps · 200 XP

MediumPro

Design a URL Shortener - LLD Interview Problem. Master encoding algorithms & redirection. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+7

30–60 min4 steps · 200 XP

MediumPro

Design an ATM System - LLD Interview Problem. Master state management & concurrent transactions. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+3

30–60 min4 steps · 200 XP

MediumPro

Design an Order Matching Engine - LLD Interview Problem. Master price-time priority & order book. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+7

30–60 min4 steps · 200 XP

MediumPro

Design an Elevator System - Single Lift - LLD Interview Problem. Master SCAN algorithm & request prioritization. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+5

30–60 min4 steps · 200 XP

HardPro

Design a Cache Manager - LLD Interview Problem. Master LRU/LFU eviction & TTL expiration. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+6

60–90 min4 steps · 300 XP

HardPro

Design a File Manager - LLD Interview Problem. Master file chunking & metadata management. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+8

60–90 min4 steps · 300 XP

HardPro

Design a Parking Lot - Multi-threaded - LLD Interview Problem. Master thread safety & deadlock prevention. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+8

60–90 min4 steps · 300 XP

HardPro

Design a Payment Processor - LLD Interview Problem. Master idempotency & transaction state management. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+7

60–90 min4 steps · 300 XP

HardPro

Design a Search Index - LLD Interview Problem. Master inverted index & relevance ranking. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+8

60–90 min4 steps · 300 XP

HardPro

Design a Task Scheduler - LLD Interview Problem. Master DAG dependencies & exponential backoff. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+7

60–90 min4 steps · 300 XP

HardPro

Design an Elevator System - Request Feasibility - LLD Interview Problem. Master route planning & feasibility checks. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+6

60–90 min4 steps · 300 XP

HardPro

Design a Music Streaming Service - LLD Interview Problem. Master playlist management & recommendations. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+8

60–90 min4 steps · 300 XP

HardPro

Design an Ngrok Tool - LLD Interview Problem. Master secure tunneling & protocol handling. Solutions in Python, Java, C++, TS, JS & C#.

Low Level DesignLLD+7

60–90 min4 steps · 300 XP

Choose your next design problem

google problems

Design a File System

Design an Elevator System

Tutorial: Design a Parking Lot System

Design a Coffee Machine

Design a JSON Parser

Design a Movie Ticket Booking System

Design a Trie (Prefix Tree)

Design a Vending Machine

Design LRU Cache

Designing a Logging Framework

Designing a Task Management System

Designing a Tic Tac Toe Game

Design a Meeting Room Reservation System

Design a Meeting Room Scheduler - List Bookings

Design a Rate Limiter

Design a Simple Elevator System - Multiple Lifts

Design a Train Platform Management System

Design a URL Shortener Service

Design an ATM System

Design an Order Matching Engine

Design Elevator Management System - Single Lift

Design a Cache Manager

Design a File Manager

Design a Parking Lot - Multi Threaded

Design a Payment Processor

Design a Search Index

Design a Task Scheduler

Design an Elevator System - Request Feasibility (Single Lift)

Design Music Streaming Service like Spotify

Design Ngrok Tool